Automatic electric drip coffee maker



Oct. 29, 1935.` A. c. wnLoox 2,018,695

AUTOMATIC ELETRIC DRI?? COFFEE MKER Filed March e, 1954 2 shet-sheet 1f* 1l I3 I iil 55 5579 17 l I 65]? 75 I8 l I| *3| l; ,l 70a 223] 37 24,ffii/- .Lagzz 035 34u33 813952 f 6 l l o u u I 44 45 94 4l l i 4Z 43AC. W'leax F191/ @a gw www Oct. 29, 1935. A.' c. wlLcvox. 2,018,695

AUTOMATIC ELECTRIC DRIP' COFFEEMAKER Filed March 8, 1934 2 sheets-sheet2 Patented 9ct. 29, i935 l 2,018,695 AUTOMATIC ELECTRIC unir COFFEEMAKER Albert C. Wilcox, 'Massillom Ohio, assignor to' The EnterpriseAluminum Company, Massillon, Ohio, a corporation Ohio Application Marchs, 1934, serial No. l714,669

s Claims. (ci. 21o-4i) The invention relates erating electrically heateddrip coffee maker, and the present application is an improvement upon myprior application, Serial No. 623,560, filed The invention in my priorapplication consists in an automatically operating electric drip coii'eemaker including a water container and a groundcoiee basket locatedbeneath the same, electric means being provided for heating the water inthe water container, siphoning means, operated by steam pressure in thewater container, being provided for discharging the Water from thecontainer through the coiee basket, means being provided for cuttingoli' the heating means when the water in the'container reaches theboiling temperature. A

The object of the present improvement is to provide means fordischarging the water from the water container through the coiee basketwhen the water reaches the boiling point, but without requiring steampressure to accomplish the same, and for simultaneously cutting oil theelectric heating element.

Another object of the improvement is to prov ide a normally closed valvein the bottom of the water container and means operated by the waterreaching the boiling point for automatically opening said valve anddischarging the water through the coiee basket and for simulteneouslycutting oi' the electric heating element.

.A further object is to provide a valve in the Water containeroperatively connected to a thermally controlled switch in the circuit tothe heating element whereby when steam from the water container contactswith the thermally controlled switch the current will be cut oi from theheating element and the valve will be opened to discharge the water fromtheV water container through the coee basket. g

A still further object of the improvement is to provide a rotary valvewith a bimetal strip for urging the same tightly against its seat as thetemperature oi the water in the water container is raised.

The above, together with other objects which will be apparent from thedrawings and the following description, or which may be later pointedout, may be attamed by constructing the improved automatic electric dripcoiee maker as illustrated .in the accompanying drawings, in whichFigure 1 is a vertical sectional view through a to an automatically op-'of the automatic electric showing the switch and valve preferredembodiment drip coffee maker, in closed position;

Fig. 2, an elevatio of the automatic thermally operated switch, shwingthe sameV in closed po- '5 sition with the cover plate removed; Fig. 3,a view similar to Fig. 2, showing the switch in open positiom' y Fig. 4,a detail sectional view of the valve, taken as on the line 4 4, Fig.. 1,the valve being shown 10 in closed position;

Fig. 5, a View similar to Fig. 4, showing the valve in open position;

Fig. 6, a transverse sectional view through the -upper end portion ofthe cover plate for the 15 switch housing and the bi-metal strip on aslightly enlarged scale, taken substantially-on the line 6 6, Fig. 2;

Fig. '7, a transverse sectional view through the switch, taken on theline l-l, Fig. 2; and 20 Fig. 8, a side elevation of the switch, partlyin section. showing the switch in open position.

Similar numerals refer to similar parts throughout the drawings.

The improved vautomatic electric drip coiee 25 maker to which theinvention pertains includes generally the water container indicated atI0, the coiee basket indicated at l l which is adapted to be detachablyconnected to the lower end of the water container, and the pot or coeebever age receptacle i2 at the upper end of which the coffee basket isarranged to be supported.

The upper open end ofthe water container may be provided with the beadI3 and is shaped to re- 8 ceive the depending skirt it of the-cover l5in l the top of which an air vent i6 may be formed to prevent a vacuumfrom being produced in the water container when thewater is dischargedtherefrom. 40

'I'he water container may be provided With'a lower shell il having theperipheral flange portion i8 tightly fitting the slightly reduced lowerend I 9 of the water container, forming a chamber at the lower end ofthe water container for containing the electric heating element 2i! bymeans n of which the Water in the container may be f heated.

This lower shell may be shoulderedas at 2i to nt within the upturnedperipheral flange 22 50 provided at the upper end of the coffee basket,and is preferably recessed as at 23 for a purpose to be later explained.'I'he bottom wall of the shell Il is preferably shouldered as at 24 tocontact with the underside of the heating element element.

valve is rotated in its seat to open `in the container I6 reaches andthe shoulder 24 of the shell and is centrally oiset as at 25 to bereceived within the central opening 26 of said heating A stud 21 islocated through the bottom wall of the Water container and through theshell I1 and is provided at its upper end with a head or flange 28between which and the bottom of the Water container may be located agasket 29. A nut 30 is provided upon the stud 21 and contacts with theshell I1 drawing the head of the stud tightly against the bottom of thewater container and clamping the electric heating element 20 between thebottom of the water container A central passage 3| is provided throughthe stud 21 forming a discharge outlet for the water container, and thelower end of the stud is concaved, forming the substantially half-roundvalve seat 32 within which the ball valve 33 is seated. The dischargeport 34 is formed through the ball 33 and arranged to register with thedischarge outlet 3-I of the stud 21 when the ball position, as shown inFig. 5.

The ball valve 33 is arranged to be held tightly seated within the valveseat 32 as by a spring 35 which is preferably formed of bimetal asillustrated. This spring may be ilxed at one end to the shell I1 as bybolts or rivets 31, the free end portion being provided with an aperture38 of .considerably l'ess diameter than the ball 33 arranged to receivethe lower side of the ball, as shown in the drawings, in order to pressthe ball tightly against the seat 32, Y.

'I'he valve mechanism may be enclosed as by the closure member 39provided with the peripheral ange 48 adapted to lit .tightly within therecess 23 of the shell I1.' This closure 39 is preferably curved orItapered downward toward its center, at which point it is provided withan aperture 4I of4 suitable size to permit the water discharged throughthe valve to pass freely therethrough.

The spreader plate 42 is in the form of a perforated disk having theupwardly offset peripheral ange 43 and is so constructed that it may, ifdesired, be placed loosely upon the top of the coffee basket or, asshown tachably engaged with headed studs 44 carried by the closuremember 39. For this purpose', the apertures 45 in the ange 43, whichengage the studs 44, may be in the form of keyhole slots to permit thespreader plate to be quickly and 'easily attached to or detached fromthe closure member.

`For the purpose of cutting ofi the current to the electric heatingelement 2l) when the water the boiling point, and at the same timeopening the valve to per mit the-boiling water to be discharged from thewater container through the coiee basket, a thermallyoperated switch isprovided. This switch may be located in an insulation housing indicatedgenerally at 46 and mounted upon one side of the water container, spacedtherefrom as illustrated in the drawings in order to permit freecirculation of alrentirely aroundthe switch housing so that the thermalelement thereof will not be operated by heat conductedor radiated fromthe water container.

This thermal element may be in the form of a .wl-bimetal strip 41located Within a chamber 48 formed in the housing and closed by theplate 49 which may be formed of metal. The chamber 48 of the switchhousing commurucateswth lend to the upper end of a in Fig. 1, may bedebeing preferably arm in open position as the interior of the watercontainer through the bleeder port 50 formed in the water container andthe inlet portl 5I in the switch housing 46.

The bimetal strip 41 may be connected at its upper end only to theswitch housing as by the 5 bolt 52 which also connects the cover plate49 to the housing, a nut 53 clamping the upper end portion of thebimetal strip to the upper portion of the cover plate 49 and a nut 54upon lthe end portion of the bolt 52 fastening the cover plate andbimetal strip to the insulation housing 46.

A headed stud 55 may be xed to an intermediate portion of the bimetalstrip and 1ocated through an aperture 56 in the cover plate 15 49 whichis of suilicient size to permit the stud to move freely therethrough,providing means for manually operating the'bimetal strip in the eventthis may be necessary or desirable. A stud `51 is fixed to the lower endof the bimetal strip 20 and is located through an aperture 58 in thecover plate B9, said stud being provided in its outer endI with a socket59 adapted to receive the rounded stud 6U upon the upper end of theinsulation arm 6 I the lower end of which is xed 25 to the shaft 62which is journaled through the bushing 63 in the insulation housing 46.Bus bars 64 are connected to the heating element 20 and are fixed to theinner ends of the bolts 65, which project through the peripheral 30flange I8 of the shell I1, as by the nuts 66. The insulation housing 46is connected to the shell by these bolts 65 and is spaced therefrom asby the bosses 61 which surround these bolts and the boss 68 at the upperend of the housing so Y35 that there may be a complete circulation ofair entirely around the switch housing, preventing the bimetal stripfrom being operated by heat conducted or radiated from the Watercontainer.

One of these bolts 40 65 is connected at its outer bus bar"69 to theother end of which is connected a contact post 18 adapted to be receivedin the usual connector plug. The other bolt 66 is connected to a con- 45tact member 1I having the angular ilange 12 which is spaced from asimilar flange 13 upon a contact member 14 connected to the contact post10a corresponding to the post 10.

A suitable guard or shield 15 may be located 50 around the posts 10 and18a and insulated therefrom as shown at 16, to receive the usualconnector plug.-

A coil spring 'I1 has, one end connected to a stud 18 inone side of theinsulation switch hous- 55 ing, the other end of the spring beinglocated in a recess 19 in the switch arm 6I. for normally urging the armto the position shown in Fig. 3, in which position the contactl stud 80.upon the armis disengaged from the contact anges 12 60 and 13 so as tohold the switch in open position.

The ball valve 33 is provided with a stem 8| fixed thereto and connectedto the shaft 62 of the switch arm as by a ball and socket jointindicated generally at 82, whereby the valve is 65 arranged to beoperated by said switch arm. With the switch arm in the closed positionas shown in Figs. 1 and 2, the ball valve is in closed position as shownin Fig. 4 and with the 4switch valve is also in open position as shownin Fig. 5. In the operation of the improved automatic electric dripcoil'ee makerkwith the switch and valve in closed position as hown inFigs. 1, 2 and 44,' the desired amount of ground coffee is 75 shown inFig. 3, the bau '10 y l the co fsljlo'wn in Fig. 1. jlof 'connec-torplug electrically connected to a jsuitable source of electric ycurrentis then connected to the'contact posts 10 and '10a and the K 2,018,695placed inthe coffee basket H and the desired famount off cold water isplaced in the water conjtainer IIll,"the parts being then assembled asAny usual and well known form ircuitto the lheating element 20 beingclosed by ritact stud `8|l bridging the gap between the contact flanges12 and 13, current is furnished to the heating element.

The water in the water container I is thus I heated by the electricheating element and when thewater reaches the boiling temperature, steamwill bedischarged from the boiling water in the water container throughthe bleeder port 50 and inlet port to the chamber 48 of the switchhousing, the steam contacting with the bimetal strip 41 and causing thesame to Warp or bend to the position shown in Fig.- 8, disengaging thesocket 59 carried thereby from the stud 60 upon the switch arm 6I,permitting the spring 11 to throw said switch arm to the open positionas shown in Figs. 3 and 8, thus disengaging the contact stud 80 from thecontact flanges 12 and.

13 and breaking the circuit to the heating element.

As the switch arm 61 is swung to the open position it will rotate theshaft-62 and through the ball and socket joint 82 and stem 8| the ballvalve 33 will be rotated to the open position as shown in Fig. 5,permitting the hot waterfrom the water container to be dischargedthrough the opening 34 in the ball, and .through the opening 4| in theclosure member 39, the water being distributedl over the spreader plate42 and through the apertures 84 therein to the coiee basket, passingthrough the ground coiee, the nished coie'e beverage dripping throughthe perforated bottom V85 of the coiee basket into the pot or receptaclel2. Any surplus of water which is not rapidly carried oif through theapertures 84 in the bottom of the spreader plate may pass out throughthe apertures 85 around the periphery thereof. It will be seen that atall times during the operation of the device, the ball 33 will be heldtightly against the seat 32 by means of the spring 35, and by formingthis spring of bimetal, it will be seen that as the temperatureincreases, the spring will warp or bend upward against the ball urgingthe same more tightly toward the seat, thus assuring a tight t betweenthe ball and seat and preventing any leakage of water from the water.container until the valve is moved to open position by the operation ofthe thermally controlled switch.

From the above it will be evident that the improved drip coiee makerdoes not depend upon steam pressure to operate the means for dischargingthe water from the water container but operates merely by the raising ofthe water to the boiling temperature, thus obviating the necessity ofproviding a steam-tight closure for the mally operated switch having arotary switch basket'.

member operated by steam produced by boiling of the water for cuttingout'said heating element and operating said valve to dischargethe waterfrom the water container through said coffee 2. A drip coiee makerincluding a Water container, a coiee basket beneath said watercontainer, an electric heating element for heating the water in-thecontainer, a concavefvalve seat at the lower end ofthe water containenaball valve rotatable in said valve seat, and a thermally operated switchhaving a rotaryvswitch member operatively connected to said ball valveand operated by steam produced by boiling of the water for cutting outsaid heating element and rotatl5 i'rig said ball valve to discharge thewater from the Water container through said-colee basket.

3. A drip colee maker including a water container, a coffee basketbeneath said water container, an electric heating element for heating 20the water in the container, a concave valve seat at the lower end of theWaterv container, a ball valve rotatable in said valve seat, a springfor holding said ball valve snugly against the valve seat, and athermally operated switch having a rotary switch member operativelyconnected to said ball valve and operated by steam produced by boilingof the water for cutting out said heating element and rotating said ballvalve to discharge the water from the water container through saidcoffee basket.

4. A drip coiee maker including a water container, a coiee basketbeneath said water container, an electric heating element for heatingthe water in the container, a concave valve seat at the lower end of thewater container, a ball valve rotatable in said valve seat, a bimetalspring for holding said ball valve snugly against the valve seat, and athermally operated switch havinga rotary switch member operativelyconnected to said ball valve and. operated by steam produced by boilingof the water for cutting out said heating element and rotating said ballvalve to discharge' the water from the water container through saidcoffee basket.

5. A drip coffee maker including a water container, a coiee basketbeneath. said water container, means for heating the water in thecontainer, a concave valve seat at the lower end of the-Water container,a ball valve rotatable in said valve seat, and a bimetal spring forholding said ball valve snugly against the valve seat.

6. A drip coffee maker including a water container, a coee basketbeneath said water container, means for heating the water in the con- 55tainer, a concave valve seat at the lower' end of the water container, aball valve rotatable in said valve seat, a bimetal spring for holdingsaid ball valve snugly against the valve seat, and thermally controlledmeans for opening said valve todischarge the water from the watercontainer through the coiee basket when the water reaches apredetermined temperature.

7. A drip coffeemaker including a water container, a coiee basketbeneath said Water container, means for heating the waterin thecontainer, a concave valve seat at the lower end of the Water container,a ball valve rotatable in said valve seat, a stem fixed to said ballvalve, thermally operated means including an arm, a shaft xed to thearm, a ball and socket joint connecting the shaft to said stem, a springnormally urging the arm toward a position to open the-valve, and abimetal member for holding the arm against movement by the spring, saidbiwhen the water in the container reaches a predetermined temperature torelease said arm and permit the spring to move the arm to a position 5to open the valve.

8. A drip coffee maker including a water container, a coffee basketbeneath said. water container, a valve at the lower end of said watercontainer,4 an electric heating element' for heating the water in thecontainer, a switch controlling said heating element, a spring fornormally urging the valve and the switch to open position, and a bimetalVmember for holding the valve and the switch against movement b'y-saidspring', said bimetal member vbeing arranged to be` operated when thewater in the container reaches a predetermined temperature to releasethe valve and switch and permit-the springl to open the valve andswitch.

9. A drip coee maker including a water con-l tainer, a colee basketbeneath the water container, electric vmeans for heating water in thecontainer, a concave valve seat at the lower end of the water container,a bail valve rotatable in the valve seat, a stem xed to said ball valve,an armoperatively connected to the stem,'a switch controlling saidheating means operated. by said arm, spring means normally urging saidarm toward a position Ato open switch, and a bimetal member for holdingthe arm against movement bythe spring, said bi metal member beingarranged to be operated when the water in the container reaches apredetermined temperature to release said arm and l5 permit the springto move the arm to a position to open the valve and the switch.

c.'wn.cox.

the valve and the y

